grep

#RegExps

• https://unix.stackexchange.com/q/181254/

# Grab urls
grep -Eo "(http|https)://[a-zA-Z0-9./?=_%:-]*" source.html | sort -u

# same but piped
grep -Eoi '<a [^>]+>' source.html |
  grep -Eo 'href="[^\"]+"' |
  grep -Eo '(http|https)://[^/"]+'

# PCRE
grep -Po '(?<=href=")[^"]*(?=")'

• grep -P lookaround expressions
• grep -Eis the same as egrep
• grep -o only outputs what has been grepped
• (http|https) is an either / or
• a-z is all lower case
• A-Z is all upper case
• . is dot
• / is the slash
• ? is ?
• = is equal sign
• _ is underscore
• % is percentage sign
• : is colon
• - is dash
• * is repeat the […] group
• sort -u will sort & remove any duplicates